1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * linux/fs/jbd2/recovery.c
4 *
5 * Written by Stephen C. Tweedie <sct@redhat.com>, 1999
6 *
7 * Copyright 1999-2000 Red Hat Software --- All Rights Reserved
8 *
9 * Journal recovery routines for the generic filesystem journaling code;
10 * part of the ext2fs journaling system.
11 */
12
13 #ifndef __KERNEL__
14 #include "jfs_user.h"
15 #else
16 #include <linux/time.h>
17 #include <linux/fs.h>
18 #include <linux/jbd2.h>
19 #include <linux/errno.h>
20 #include <linux/crc32.h>
21 #include <linux/blkdev.h>
22 #endif
23
24 /*
25 * Maintain information about the progress of the recovery job, so that
26 * the different passes can carry information between them.
27 */
28 struct recovery_info
29 {
30 tid_t start_transaction;
31 tid_t end_transaction;
32
33 int nr_replays;
34 int nr_revokes;
35 int nr_revoke_hits;
36 };
37
38 static int do_one_pass(journal_t *journal,
39 struct recovery_info *info, enum passtype pass);
40 static int scan_revoke_records(journal_t *, struct buffer_head *,
41 tid_t, struct recovery_info *);
42
43 #ifdef __KERNEL__
44
45 /* Release readahead buffers after use */
journal_brelse_array(struct buffer_head * b[],int n)46 static void journal_brelse_array(struct buffer_head *b[], int n)
47 {
48 while (--n >= 0)
49 brelse (b[n]);
50 }
51
52
53 /*
54 * When reading from the journal, we are going through the block device
55 * layer directly and so there is no readahead being done for us. We
56 * need to implement any readahead ourselves if we want it to happen at
57 * all. Recovery is basically one long sequential read, so make sure we
58 * do the IO in reasonably large chunks.
59 *
60 * This is not so critical that we need to be enormously clever about
61 * the readahead size, though. 128K is a purely arbitrary, good-enough
62 * fixed value.
63 */
64
65 #define MAXBUF 8
do_readahead(journal_t * journal,unsigned int start)66 static int do_readahead(journal_t *journal, unsigned int start)
67 {
68 int err;
69 unsigned int max, nbufs, next;
70 unsigned long long blocknr;
71 struct buffer_head *bh;
72
73 struct buffer_head * bufs[MAXBUF];
74
75 /* Do up to 128K of readahead */
76 max = start + (128 * 1024 / journal->j_blocksize);
77 if (max > journal->j_total_len)
78 max = journal->j_total_len;
79
80 /* Do the readahead itself. We'll submit MAXBUF buffer_heads at
81 * a time to the block device IO layer. */
82
83 nbufs = 0;
84
85 for (next = start; next < max; next++) {
86 err = jbd2_journal_bmap(journal, next, &blocknr);
87
88 if (err) {
89 printk(KERN_ERR "JBD2: bad block at offset %u\n",
90 next);
91 goto failed;
92 }
93
94 bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize);
95 if (!bh) {
96 err = -ENOMEM;
97 goto failed;
98 }
99
100 if (!buffer_uptodate(bh) && !buffer_locked(bh)) {
101 bufs[nbufs++] = bh;
102 if (nbufs == MAXBUF) {
103 ll_rw_block(REQ_OP_READ, 0, nbufs, bufs);
104 journal_brelse_array(bufs, nbufs);
105 nbufs = 0;
106 }
107 } else
108 brelse(bh);
109 }
110
111 if (nbufs)
112 ll_rw_block(REQ_OP_READ, 0, nbufs, bufs);
113 err = 0;
114
115 failed:
116 if (nbufs)
117 journal_brelse_array(bufs, nbufs);
118 return err;
119 }
120
121 #endif /* __KERNEL__ */
122
123
124 /*
125 * Read a block from the journal
126 */
127
jread(struct buffer_head ** bhp,journal_t * journal,unsigned int offset)128 static int jread(struct buffer_head **bhp, journal_t *journal,
129 unsigned int offset)
130 {
131 int err;
132 unsigned long long blocknr;
133 struct buffer_head *bh;
134
135 *bhp = NULL;
136
137 if (offset >= journal->j_total_len) {
138 printk(KERN_ERR "JBD2: corrupted journal superblock\n");
139 return -EFSCORRUPTED;
140 }
141
142 err = jbd2_journal_bmap(journal, offset, &blocknr);
143
144 if (err) {
145 printk(KERN_ERR "JBD2: bad block at offset %u\n",
146 offset);
147 return err;
148 }
149
150 bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize);
151 if (!bh)
152 return -ENOMEM;
153
154 if (!buffer_uptodate(bh)) {
155 /* If this is a brand new buffer, start readahead.
156 Otherwise, we assume we are already reading it. */
157 if (!buffer_req(bh))
158 do_readahead(journal, offset);
159 wait_on_buffer(bh);
160 }
161
162 if (!buffer_uptodate(bh)) {
163 printk(KERN_ERR "JBD2: Failed to read block at offset %u\n",
164 offset);
165 brelse(bh);
166 return -EIO;
167 }
168
169 *bhp = bh;
170 return 0;
171 }
172
jbd2_descriptor_block_csum_verify(journal_t * j,void * buf)173 static int jbd2_descriptor_block_csum_verify(journal_t *j, void *buf)
174 {
175 struct jbd2_journal_block_tail *tail;
176 __be32 provided;
177 __u32 calculated;
178
179 if (!jbd2_journal_has_csum_v2or3(j))
180 return 1;
181
182 tail = (struct jbd2_journal_block_tail *)(buf + j->j_blocksize -
183 sizeof(struct jbd2_journal_block_tail));
184 provided = tail->t_checksum;
185 tail->t_checksum = 0;
186 calculated = jbd2_chksum(j, j->j_csum_seed, buf, j->j_blocksize);
187 tail->t_checksum = provided;
188
189 return provided == cpu_to_be32(calculated);
190 }
191
192 /*
193 * Count the number of in-use tags in a journal descriptor block.
194 */
195
count_tags(journal_t * journal,struct buffer_head * bh)196 static int count_tags(journal_t *journal, struct buffer_head *bh)
197 {
198 char * tagp;
199 journal_block_tag_t * tag;
200 int nr = 0, size = journal->j_blocksize;
201 int tag_bytes = journal_tag_bytes(journal);
202
203 if (jbd2_journal_has_csum_v2or3(journal))
204 size -= sizeof(struct jbd2_journal_block_tail);
205
206 tagp = &bh->b_data[sizeof(journal_header_t)];
207
208 while ((tagp - bh->b_data + tag_bytes) <= size) {
209 tag = (journal_block_tag_t *) tagp;
210
211 nr++;
212 tagp += tag_bytes;
213 if (!(tag->t_flags & cpu_to_be16(JBD2_FLAG_SAME_UUID)))
214 tagp += 16;
215
216 if (tag->t_flags & cpu_to_be16(JBD2_FLAG_LAST_TAG))
217 break;
218 }
219
220 return nr;
221 }
222
223
224 /* Make sure we wrap around the log correctly! */
225 #define wrap(journal, var) \
226 do { \
227 unsigned long _wrap_last = \
228 jbd2_has_feature_fast_commit(journal) ? \
229 (journal)->j_fc_last : (journal)->j_last; \
230 \
231 if (var >= _wrap_last) \
232 var -= (_wrap_last - (journal)->j_first); \
233 } while (0)
234
fc_do_one_pass(journal_t * journal,struct recovery_info * info,enum passtype pass)235 static int fc_do_one_pass(journal_t *journal,
236 struct recovery_info *info, enum passtype pass)
237 {
238 unsigned int expected_commit_id = info->end_transaction;
239 unsigned long next_fc_block;
240 struct buffer_head *bh;
241 int err = 0;
242
243 next_fc_block = journal->j_fc_first;
244 if (!journal->j_fc_replay_callback)
245 return 0;
246
247 while (next_fc_block <= journal->j_fc_last) {
248 jbd_debug(3, "Fast commit replay: next block %ld\n",
249 next_fc_block);
250 err = jread(&bh, journal, next_fc_block);
251 if (err) {
252 jbd_debug(3, "Fast commit replay: read error\n");
253 break;
254 }
255
256 err = journal->j_fc_replay_callback(journal, bh, pass,
257 next_fc_block - journal->j_fc_first,
258 expected_commit_id);
259 brelse(bh);
260 next_fc_block++;
261 if (err < 0 || err == JBD2_FC_REPLAY_STOP)
262 break;
263 err = 0;
264 }
265
266 if (err)
267 jbd_debug(3, "Fast commit replay failed, err = %d\n", err);
268
269 return err;
270 }
271
272 /**
273 * jbd2_journal_recover - recovers a on-disk journal
274 * @journal: the journal to recover
275 *
276 * The primary function for recovering the log contents when mounting a
277 * journaled device.
278 *
279 * Recovery is done in three passes. In the first pass, we look for the
280 * end of the log. In the second, we assemble the list of revoke
281 * blocks. In the third and final pass, we replay any un-revoked blocks
282 * in the log.
283 */
jbd2_journal_recover(journal_t * journal)284 int jbd2_journal_recover(journal_t *journal)
285 {
286 int err, err2;
287 journal_superblock_t * sb;
288
289 struct recovery_info info;
290 errseq_t wb_err;
291 struct address_space *mapping;
292
293 memset(&info, 0, sizeof(info));
294 sb = journal->j_superblock;
295
296 /*
297 * The journal superblock's s_start field (the current log head)
298 * is always zero if, and only if, the journal was cleanly
299 * unmounted.
300 */
301
302 if (!sb->s_start) {
303 jbd_debug(1, "No recovery required, last transaction %d\n",
304 be32_to_cpu(sb->s_sequence));
305 journal->j_transaction_sequence = be32_to_cpu(sb->s_sequence) + 1;
306 return 0;
307 }
308
309 wb_err = 0;
310 mapping = journal->j_fs_dev->bd_inode->i_mapping;
311 errseq_check_and_advance(&mapping->wb_err, &wb_err);
312 err = do_one_pass(journal, &info, PASS_SCAN);
313 if (!err)
314 err = do_one_pass(journal, &info, PASS_REVOKE);
315 if (!err)
316 err = do_one_pass(journal, &info, PASS_REPLAY);
317
318 jbd_debug(1, "JBD2: recovery, exit status %d, "
319 "recovered transactions %u to %u\n",
320 err, info.start_transaction, info.end_transaction);
321 jbd_debug(1, "JBD2: Replayed %d and revoked %d/%d blocks\n",
322 info.nr_replays, info.nr_revoke_hits, info.nr_revokes);
323
324 /* Restart the log at the next transaction ID, thus invalidating
325 * any existing commit records in the log. */
326 journal->j_transaction_sequence = ++info.end_transaction;
327
328 jbd2_journal_clear_revoke(journal);
329 err2 = sync_blockdev(journal->j_fs_dev);
330 if (!err)
331 err = err2;
332 err2 = errseq_check_and_advance(&mapping->wb_err, &wb_err);
333 if (!err)
334 err = err2;
335 /* Make sure all replayed data is on permanent storage */
336 if (journal->j_flags & JBD2_BARRIER) {
337 err2 = blkdev_issue_flush(journal->j_fs_dev, GFP_KERNEL);
338 if (!err)
339 err = err2;
340 }
341 return err;
342 }
343
344 /**
345 * jbd2_journal_skip_recovery - Start journal and wipe exiting records
346 * @journal: journal to startup
347 *
348 * Locate any valid recovery information from the journal and set up the
349 * journal structures in memory to ignore it (presumably because the
350 * caller has evidence that it is out of date).
351 * This function doesn't appear to be exported..
352 *
353 * We perform one pass over the journal to allow us to tell the user how
354 * much recovery information is being erased, and to let us initialise
355 * the journal transaction sequence numbers to the next unused ID.
356 */
jbd2_journal_skip_recovery(journal_t * journal)357 int jbd2_journal_skip_recovery(journal_t *journal)
358 {
359 int err;
360
361 struct recovery_info info;
362
363 memset (&info, 0, sizeof(info));
364
365 err = do_one_pass(journal, &info, PASS_SCAN);
366
367 if (err) {
368 printk(KERN_ERR "JBD2: error %d scanning journal\n", err);
369 ++journal->j_transaction_sequence;
370 } else {
371 #ifdef CONFIG_JBD2_DEBUG
372 int dropped = info.end_transaction -
373 be32_to_cpu(journal->j_superblock->s_sequence);
374 jbd_debug(1,
375 "JBD2: ignoring %d transaction%s from the journal.\n",
376 dropped, (dropped == 1) ? "" : "s");
377 #endif
378 journal->j_transaction_sequence = ++info.end_transaction;
379 }
380
381 journal->j_tail = 0;
382 return err;
383 }
384
read_tag_block(journal_t * journal,journal_block_tag_t * tag)385 static inline unsigned long long read_tag_block(journal_t *journal,
386 journal_block_tag_t *tag)
387 {
388 unsigned long long block = be32_to_cpu(tag->t_blocknr);
389 if (jbd2_has_feature_64bit(journal))
390 block |= (u64)be32_to_cpu(tag->t_blocknr_high) << 32;
391 return block;
392 }
393
394 /*
395 * calc_chksums calculates the checksums for the blocks described in the
396 * descriptor block.
397 */
calc_chksums(journal_t * journal,struct buffer_head * bh,unsigned long * next_log_block,__u32 * crc32_sum)398 static int calc_chksums(journal_t *journal, struct buffer_head *bh,
399 unsigned long *next_log_block, __u32 *crc32_sum)
400 {
401 int i, num_blks, err;
402 unsigned long io_block;
403 struct buffer_head *obh;
404
405 num_blks = count_tags(journal, bh);
406 /* Calculate checksum of the descriptor block. */
407 *crc32_sum = crc32_be(*crc32_sum, (void *)bh->b_data, bh->b_size);
408
409 for (i = 0; i < num_blks; i++) {
410 io_block = (*next_log_block)++;
411 wrap(journal, *next_log_block);
412 err = jread(&obh, journal, io_block);
413 if (err) {
414 printk(KERN_ERR "JBD2: IO error %d recovering block "
415 "%lu in log\n", err, io_block);
416 return 1;
417 } else {
418 *crc32_sum = crc32_be(*crc32_sum, (void *)obh->b_data,
419 obh->b_size);
420 }
421 put_bh(obh);
422 }
423 return 0;
424 }
425
jbd2_commit_block_csum_verify(journal_t * j,void * buf)426 static int jbd2_commit_block_csum_verify(journal_t *j, void *buf)
427 {
428 struct commit_header *h;
429 __be32 provided;
430 __u32 calculated;
431
432 if (!jbd2_journal_has_csum_v2or3(j))
433 return 1;
434
435 h = buf;
436 provided = h->h_chksum[0];
437 h->h_chksum[0] = 0;
438 calculated = jbd2_chksum(j, j->j_csum_seed, buf, j->j_blocksize);
439 h->h_chksum[0] = provided;
440
441 return provided == cpu_to_be32(calculated);
442 }
443
jbd2_block_tag_csum_verify(journal_t * j,journal_block_tag_t * tag,void * buf,__u32 sequence)444 static int jbd2_block_tag_csum_verify(journal_t *j, journal_block_tag_t *tag,
445 void *buf, __u32 sequence)
446 {
447 journal_block_tag3_t *tag3 = (journal_block_tag3_t *)tag;
448 __u32 csum32;
449 __be32 seq;
450
451 if (!jbd2_journal_has_csum_v2or3(j))
452 return 1;
453
454 seq = cpu_to_be32(sequence);
455 csum32 = jbd2_chksum(j, j->j_csum_seed, (__u8 *)&seq, sizeof(seq));
456 csum32 = jbd2_chksum(j, csum32, buf, j->j_blocksize);
457
458 if (jbd2_has_feature_csum3(j))
459 return tag3->t_checksum == cpu_to_be32(csum32);
460 else
461 return tag->t_checksum == cpu_to_be16(csum32);
462 }
463
do_one_pass(journal_t * journal,struct recovery_info * info,enum passtype pass)464 static int do_one_pass(journal_t *journal,
465 struct recovery_info *info, enum passtype pass)
466 {
467 unsigned int first_commit_ID, next_commit_ID;
468 unsigned long next_log_block;
469 int err, success = 0;
470 journal_superblock_t * sb;
471 journal_header_t * tmp;
472 struct buffer_head * bh;
473 unsigned int sequence;
474 int blocktype;
475 int tag_bytes = journal_tag_bytes(journal);
476 __u32 crc32_sum = ~0; /* Transactional Checksums */
477 int descr_csum_size = 0;
478 int block_error = 0;
479 bool need_check_commit_time = false;
480 __u64 last_trans_commit_time = 0, commit_time;
481
482 /*
483 * First thing is to establish what we expect to find in the log
484 * (in terms of transaction IDs), and where (in terms of log
485 * block offsets): query the superblock.
486 */
487
488 sb = journal->j_superblock;
489 next_commit_ID = be32_to_cpu(sb->s_sequence);
490 next_log_block = be32_to_cpu(sb->s_start);
491
492 first_commit_ID = next_commit_ID;
493 if (pass == PASS_SCAN)
494 info->start_transaction = first_commit_ID;
495
496 jbd_debug(1, "Starting recovery pass %d\n", pass);
497
498 /*
499 * Now we walk through the log, transaction by transaction,
500 * making sure that each transaction has a commit block in the
501 * expected place. Each complete transaction gets replayed back
502 * into the main filesystem.
503 */
504
505 while (1) {
506 int flags;
507 char * tagp;
508 journal_block_tag_t * tag;
509 struct buffer_head * obh;
510 struct buffer_head * nbh;
511
512 cond_resched();
513
514 /* If we already know where to stop the log traversal,
515 * check right now that we haven't gone past the end of
516 * the log. */
517
518 if (pass != PASS_SCAN)
519 if (tid_geq(next_commit_ID, info->end_transaction))
520 break;
521
522 jbd_debug(2, "Scanning for sequence ID %u at %lu/%lu\n",
523 next_commit_ID, next_log_block,
524 jbd2_has_feature_fast_commit(journal) ?
525 journal->j_fc_last : journal->j_last);
526
527 /* Skip over each chunk of the transaction looking
528 * either the next descriptor block or the final commit
529 * record. */
530
531 jbd_debug(3, "JBD2: checking block %ld\n", next_log_block);
532 err = jread(&bh, journal, next_log_block);
533 if (err)
534 goto failed;
535
536 next_log_block++;
537 wrap(journal, next_log_block);
538
539 /* What kind of buffer is it?
540 *
541 * If it is a descriptor block, check that it has the
542 * expected sequence number. Otherwise, we're all done
543 * here. */
544
545 tmp = (journal_header_t *)bh->b_data;
546
547 if (tmp->h_magic != cpu_to_be32(JBD2_MAGIC_NUMBER)) {
548 brelse(bh);
549 break;
550 }
551
552 blocktype = be32_to_cpu(tmp->h_blocktype);
553 sequence = be32_to_cpu(tmp->h_sequence);
554 jbd_debug(3, "Found magic %d, sequence %d\n",
555 blocktype, sequence);
556
557 if (sequence != next_commit_ID) {
558 brelse(bh);
559 break;
560 }
561
562 /* OK, we have a valid descriptor block which matches
563 * all of the sequence number checks. What are we going
564 * to do with it? That depends on the pass... */
565
566 switch(blocktype) {
567 case JBD2_DESCRIPTOR_BLOCK:
568 /* Verify checksum first */
569 if (jbd2_journal_has_csum_v2or3(journal))
570 descr_csum_size =
571 sizeof(struct jbd2_journal_block_tail);
572 if (descr_csum_size > 0 &&
573 !jbd2_descriptor_block_csum_verify(journal,
574 bh->b_data)) {
575 /*
576 * PASS_SCAN can see stale blocks due to lazy
577 * journal init. Don't error out on those yet.
578 */
579 if (pass != PASS_SCAN) {
580 pr_err("JBD2: Invalid checksum recovering block %lu in log\n",
581 next_log_block);
582 err = -EFSBADCRC;
583 brelse(bh);
584 goto failed;
585 }
586 need_check_commit_time = true;
587 jbd_debug(1,
588 "invalid descriptor block found in %lu\n",
589 next_log_block);
590 }
591
592 /* If it is a valid descriptor block, replay it
593 * in pass REPLAY; if journal_checksums enabled, then
594 * calculate checksums in PASS_SCAN, otherwise,
595 * just skip over the blocks it describes. */
596 if (pass != PASS_REPLAY) {
597 if (pass == PASS_SCAN &&
598 jbd2_has_feature_checksum(journal) &&
599 !need_check_commit_time &&
600 !info->end_transaction) {
601 if (calc_chksums(journal, bh,
602 &next_log_block,
603 &crc32_sum)) {
604 put_bh(bh);
605 break;
606 }
607 put_bh(bh);
608 continue;
609 }
610 next_log_block += count_tags(journal, bh);
611 wrap(journal, next_log_block);
612 put_bh(bh);
613 continue;
614 }
615
616 /* A descriptor block: we can now write all of
617 * the data blocks. Yay, useful work is finally
618 * getting done here! */
619
620 tagp = &bh->b_data[sizeof(journal_header_t)];
621 while ((tagp - bh->b_data + tag_bytes)
622 <= journal->j_blocksize - descr_csum_size) {
623 unsigned long io_block;
624
625 tag = (journal_block_tag_t *) tagp;
626 flags = be16_to_cpu(tag->t_flags);
627
628 io_block = next_log_block++;
629 wrap(journal, next_log_block);
630 err = jread(&obh, journal, io_block);
631 if (err) {
632 /* Recover what we can, but
633 * report failure at the end. */
634 success = err;
635 printk(KERN_ERR
636 "JBD2: IO error %d recovering "
637 "block %ld in log\n",
638 err, io_block);
639 } else {
640 unsigned long long blocknr;
641
642 J_ASSERT(obh != NULL);
643 blocknr = read_tag_block(journal,
644 tag);
645
646 /* If the block has been
647 * revoked, then we're all done
648 * here. */
649 if (jbd2_journal_test_revoke
650 (journal, blocknr,
651 next_commit_ID)) {
652 brelse(obh);
653 ++info->nr_revoke_hits;
654 goto skip_write;
655 }
656
657 /* Look for block corruption */
658 if (!jbd2_block_tag_csum_verify(
659 journal, tag, obh->b_data,
660 be32_to_cpu(tmp->h_sequence))) {
661 brelse(obh);
662 success = -EFSBADCRC;
663 printk(KERN_ERR "JBD2: Invalid "
664 "checksum recovering "
665 "data block %llu in "
666 "log\n", blocknr);
667 block_error = 1;
668 goto skip_write;
669 }
670
671 /* Find a buffer for the new
672 * data being restored */
673 nbh = __getblk(journal->j_fs_dev,
674 blocknr,
675 journal->j_blocksize);
676 if (nbh == NULL) {
677 printk(KERN_ERR
678 "JBD2: Out of memory "
679 "during recovery.\n");
680 err = -ENOMEM;
681 brelse(bh);
682 brelse(obh);
683 goto failed;
684 }
685
686 lock_buffer(nbh);
687 memcpy(nbh->b_data, obh->b_data,
688 journal->j_blocksize);
689 if (flags & JBD2_FLAG_ESCAPE) {
690 *((__be32 *)nbh->b_data) =
691 cpu_to_be32(JBD2_MAGIC_NUMBER);
692 }
693
694 BUFFER_TRACE(nbh, "marking dirty");
695 set_buffer_uptodate(nbh);
696 mark_buffer_dirty(nbh);
697 BUFFER_TRACE(nbh, "marking uptodate");
698 ++info->nr_replays;
699 /* ll_rw_block(WRITE, 1, &nbh); */
700 unlock_buffer(nbh);
701 brelse(obh);
702 brelse(nbh);
703 }
704
705 skip_write:
706 tagp += tag_bytes;
707 if (!(flags & JBD2_FLAG_SAME_UUID))
708 tagp += 16;
709
710 if (flags & JBD2_FLAG_LAST_TAG)
711 break;
712 }
713
714 brelse(bh);
715 continue;
716
717 case JBD2_COMMIT_BLOCK:
718 /* How to differentiate between interrupted commit
719 * and journal corruption ?
720 *
721 * {nth transaction}
722 * Checksum Verification Failed
723 * |
724 * ____________________
725 * | |
726 * async_commit sync_commit
727 * | |
728 * | GO TO NEXT "Journal Corruption"
729 * | TRANSACTION
730 * |
731 * {(n+1)th transanction}
732 * |
733 * _______|______________
734 * | |
735 * Commit block found Commit block not found
736 * | |
737 * "Journal Corruption" |
738 * _____________|_________
739 * | |
740 * nth trans corrupt OR nth trans
741 * and (n+1)th interrupted interrupted
742 * before commit block
743 * could reach the disk.
744 * (Cannot find the difference in above
745 * mentioned conditions. Hence assume
746 * "Interrupted Commit".)
747 */
748 commit_time = be64_to_cpu(
749 ((struct commit_header *)bh->b_data)->h_commit_sec);
750 /*
751 * If need_check_commit_time is set, it means we are in
752 * PASS_SCAN and csum verify failed before. If
753 * commit_time is increasing, it's the same journal,
754 * otherwise it is stale journal block, just end this
755 * recovery.
756 */
757 if (need_check_commit_time) {
758 if (commit_time >= last_trans_commit_time) {
759 pr_err("JBD2: Invalid checksum found in transaction %u\n",
760 next_commit_ID);
761 err = -EFSBADCRC;
762 brelse(bh);
763 goto failed;
764 }
765 ignore_crc_mismatch:
766 /*
767 * It likely does not belong to same journal,
768 * just end this recovery with success.
769 */
770 jbd_debug(1, "JBD2: Invalid checksum ignored in transaction %u, likely stale data\n",
771 next_commit_ID);
772 err = 0;
773 brelse(bh);
774 goto done;
775 }
776
777 /*
778 * Found an expected commit block: if checksums
779 * are present, verify them in PASS_SCAN; else not
780 * much to do other than move on to the next sequence
781 * number.
782 */
783 if (pass == PASS_SCAN &&
784 jbd2_has_feature_checksum(journal)) {
785 struct commit_header *cbh =
786 (struct commit_header *)bh->b_data;
787 unsigned found_chksum =
788 be32_to_cpu(cbh->h_chksum[0]);
789
790 if (info->end_transaction) {
791 journal->j_failed_commit =
792 info->end_transaction;
793 brelse(bh);
794 break;
795 }
796
797 /* Neither checksum match nor unused? */
798 if (!((crc32_sum == found_chksum &&
799 cbh->h_chksum_type ==
800 JBD2_CRC32_CHKSUM &&
801 cbh->h_chksum_size ==
802 JBD2_CRC32_CHKSUM_SIZE) ||
803 (cbh->h_chksum_type == 0 &&
804 cbh->h_chksum_size == 0 &&
805 found_chksum == 0)))
806 goto chksum_error;
807
808 crc32_sum = ~0;
809 }
810 if (pass == PASS_SCAN &&
811 !jbd2_commit_block_csum_verify(journal,
812 bh->b_data)) {
813 chksum_error:
814 if (commit_time < last_trans_commit_time)
815 goto ignore_crc_mismatch;
816 info->end_transaction = next_commit_ID;
817
818 if (!jbd2_has_feature_async_commit(journal)) {
819 journal->j_failed_commit =
820 next_commit_ID;
821 brelse(bh);
822 break;
823 }
824 }
825 if (pass == PASS_SCAN)
826 last_trans_commit_time = commit_time;
827 brelse(bh);
828 next_commit_ID++;
829 continue;
830
831 case JBD2_REVOKE_BLOCK:
832 /*
833 * Check revoke block crc in pass_scan, if csum verify
834 * failed, check commit block time later.
835 */
836 if (pass == PASS_SCAN &&
837 !jbd2_descriptor_block_csum_verify(journal,
838 bh->b_data)) {
839 jbd_debug(1, "JBD2: invalid revoke block found in %lu\n",
840 next_log_block);
841 need_check_commit_time = true;
842 }
843 /* If we aren't in the REVOKE pass, then we can
844 * just skip over this block. */
845 if (pass != PASS_REVOKE) {
846 brelse(bh);
847 continue;
848 }
849
850 err = scan_revoke_records(journal, bh,
851 next_commit_ID, info);
852 brelse(bh);
853 if (err)
854 goto failed;
855 continue;
856
857 default:
858 jbd_debug(3, "Unrecognised magic %d, end of scan.\n",
859 blocktype);
860 brelse(bh);
861 goto done;
862 }
863 }
864
865 done:
866 /*
867 * We broke out of the log scan loop: either we came to the
868 * known end of the log or we found an unexpected block in the
869 * log. If the latter happened, then we know that the "current"
870 * transaction marks the end of the valid log.
871 */
872
873 if (pass == PASS_SCAN) {
874 if (!info->end_transaction)
875 info->end_transaction = next_commit_ID;
876 } else {
877 /* It's really bad news if different passes end up at
878 * different places (but possible due to IO errors). */
879 if (info->end_transaction != next_commit_ID) {
880 printk(KERN_ERR "JBD2: recovery pass %d ended at "
881 "transaction %u, expected %u\n",
882 pass, next_commit_ID, info->end_transaction);
883 if (!success)
884 success = -EIO;
885 }
886 }
887
888 if (jbd2_has_feature_fast_commit(journal) && pass != PASS_REVOKE) {
889 err = fc_do_one_pass(journal, info, pass);
890 if (err)
891 success = err;
892 }
893
894 if (block_error && success == 0)
895 success = -EIO;
896 return success;
897
898 failed:
899 return err;
900 }
901
902 /* Scan a revoke record, marking all blocks mentioned as revoked. */
903
scan_revoke_records(journal_t * journal,struct buffer_head * bh,tid_t sequence,struct recovery_info * info)904 static int scan_revoke_records(journal_t *journal, struct buffer_head *bh,
905 tid_t sequence, struct recovery_info *info)
906 {
907 jbd2_journal_revoke_header_t *header;
908 int offset, max;
909 int csum_size = 0;
910 __u32 rcount;
911 int record_len = 4;
912
913 header = (jbd2_journal_revoke_header_t *) bh->b_data;
914 offset = sizeof(jbd2_journal_revoke_header_t);
915 rcount = be32_to_cpu(header->r_count);
916
917 if (jbd2_journal_has_csum_v2or3(journal))
918 csum_size = sizeof(struct jbd2_journal_block_tail);
919 if (rcount > journal->j_blocksize - csum_size)
920 return -EINVAL;
921 max = rcount;
922
923 if (jbd2_has_feature_64bit(journal))
924 record_len = 8;
925
926 while (offset + record_len <= max) {
927 unsigned long long blocknr;
928 int err;
929
930 if (record_len == 4)
931 blocknr = be32_to_cpu(* ((__be32 *) (bh->b_data+offset)));
932 else
933 blocknr = be64_to_cpu(* ((__be64 *) (bh->b_data+offset)));
934 offset += record_len;
935 err = jbd2_journal_set_revoke(journal, blocknr, sequence);
936 if (err)
937 return err;
938 ++info->nr_revokes;
939 }
940 return 0;
941 }
942